The invention relates to a hand-held aerosol dispenser, and more particularly a hand-held aerosol dispenser for a therapeutic liquid used in inhalation therapy.
A hand-held aerosol dispenser for automizing therapeutic liquid, which is held by hand by patients for treatment at home is disclosed, for example, in the German Utility Patent 90 11 768. In the device according to the prior art, a reservoir for the liquid to be atomized is an integral part of the housing. Until now, the patient prepared for the inhalation by mixing an amount of medication and water required for one or several inhalations. The mixture was then transferred to the aerosol dispenser, after which the patient commenced with the inhalation.
Especially with asthmatics suffering an acute attack, this time-consuming preliminary work is beset by the problem that because of the sudden respiratory distress that increases rapidly, the patient panics and, as a result, is often not in a position to carry out the preparations for the necessary inhalation.
As an alternative treatment, an emergency powder inhalation may be used by the asthmatic. However, as a rule, only a medication of a related type is available. Moreover, the dry powder inhalation in most cases exerts a strongly irritating effect on the already damaged bronchia.
Furthermore, simple tap water has been used in the prior art, for moistening the bronchial region as well as for preparing a mixture of water and the drug. Such water may prove unsuitable for inhalation therapy. Although there are usually no complications when such water is used for external and oral applications, the impurities contained in tap water can, in certain instances, lead to serious infections in the lung.
U.S. Pat. No. 3,915,386 discloses a room humidifier, which also works with an atomizing nozzle. Such room humidifiers are used for the purpose of optimizing the room atmosphere in sensitive areas, such as in operating rooms. The known humidifier has a reservoir, which can be screwed into the housing from below and can contain sterilized water. The known apparatus is not suitable for use as a hand-held device, because the reservoir has a capacity of about 1 liter and is also not intended for atomizing a drug mixture, since such use would be inappropriate for room humidification.